Vehicle windscreen wiping mechanisms

ABSTRACT

A mechanism for controlling the operating cycle of a wiper blade for cleaning a vehicle windscreen comprises a wiper arm mounted on a carrier, which is connected to a drive rod, or belt for linear reciprocation lengthwise of an edge of the windscreen to be cleaned, the carrier engaging guide means whereby, at one end of the movement, the carrier and arm are caused to move angularly.

ilited States atent Finley VEHICLE WINDSCREEN WWHNG MECHANISMS Inventor:Gilbert Ralph Finley, Solihull, En-

gland Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England Filed: Dec. 18, 1969 Appl. No.: 886,424

Foreign Application Priority Data Jan. 3, 1969 Great Britain ..537/69US. Cl. ..15/250.16, l5/250.24, l5/250.26 Int. Cl. ..B60S l/02 Field ofSearch ..15/250.16, 250.24, 250.25,

[451 Aug. 29, 1972 References Ci UNITED STATES PATENTS 2,063,055 12/1936Shaw ..l5/250.24 X 3,078,494 2/1963 Price ..l5/250.26 X 3,505,702 4/1970Omlie et al. ..l5/250.24 X

Primary Examiner-Peter Feldman Attorney-Holman & Stern TRACT A mechanismfor controlling the operating cycle of a wiper blade for cleaning avehicle windscreen comprises a wiper arm mounted on a carrier, which isconnected to a drive rod, or belt for linear reciprocation lengthwise ofan edge of the windscreen to be cleaned, the carrier engaging guidemeans whereby, at one end of the movement, the carrier and arm arecaused to move angularly.

7 Claims, 6 Drawing PATENTEUAUGZQIHYZ $686,706

SHEET 3 [IF 3 INVENTOR M 3 y D ATTE EN EYS SMS This invention relates tomechanisms for controlling the operating cycle of wiper blades forcleaning vehicle windscreens.

The object of the invention is to provide a mechanism for this purposewhich enables maximum area of the glass screen to be cleaned.

According to the present invention a mechanism for controlling theoperating cycle of a wiper blade for cleaning a vehicle windscreencomprises, a wiper blade carrier, means for moving the carriersubstantially linearly with respect to one edge of the windscreen to becleaned, and guide means whereby said linear movement is converted intoangular movement of the blade carrier over a portion of the cycle.

The invention will now be described by way of example with reference tothe accompanying drawings in which:

FIG. 1 is a view of a mechanism for a single wiper blade constructed inaccordance with the invention, but some of the parts omitted forclarity,

FIG. 2 is an end view of the mechanism shown in FIG. 1,

FIG. 3 is a small scale view of an alternative form of mechanism inaccordance with the invention,

FIG. 4 is a diagrammatic representation of areas of the vehiclewindscreen which can be wiped by the mechanism shown in FIG. 3,

FIG. 5 is a small scale diagrammatic view of an alternative forrn ofapparatus, and

FIG. 6 represents the areas wiped by the mechanism in FIG. 5.

With reference to the construction illustrated in FIGS. 1 and 2 themechanism is intended to control a single wiper blade which is carriedby a blade carrier 10. The blade carrier is pivotally mounted on one armof a bell crank lever 11 the pivotal connection between the bell cranklever arm and the blade carrier being substantially parallel with thesurface of a windscreen with which the mechanism is associated.

At the junction of its arms, the bell crank lever is pivotally mountedon a nut member 12 which has an internal pin (not shown) engaging in acontinuous groove 13 in a cylindrical drive shaft 14. The continuousgroove 13 is of double helical form, the helices being of opposite hand.At the ends of the helices there are portions of the groove 13 whichjoin the ends of the opposite helices.

In use, when the drive shaft 14 is rotated, the nut member 12 travelsfrom end to the other of one of the helices and is then transferred bythe appropriate groove portion 15 to the other helix, whereupon the nutmember 12 moves back to said one end. This cycle is repeatedcontinuously until the shaft 14 is brought to rest. To drive the shaft14 there is an electric motor 16.

The nut 12 and bell crank lever 11 are connected to a flanged channelshaped part 17, which interengages with a T-shaped portion of a rail 18,which is thus of complementary cross-sectional shape to prevent tiltingof the carrier and nut. The rail 18 is secured to a fixed part of thevehicle and extends substantially parallel with one edge (for examplethe lower edge) of the windscreen to be cleaned.

The rail 18 defines a channel 19 extending the full length thereof,which forms a guide for a roller 20 which is carried through a pin 21 onthe other arm of the bell crank lever 1 1.

Over the greater part of its length, the channel 19 is parallel to theshaft 1 but at one of its ends there is an S-shaped extension of thechannel indicated in FIG. 1 at 22.

The arrangement is such that the roller 20 engages in the extension 22of the channel 19, before the nut member 17 has reached the end of itstravel, and when the roller 20 moves into the extension 22, it is movedaway from the longitudinal axis of the shaft 14, thus causing the bellcrank lever 11 to pivot on the nut member 112.

In use, when the roller 20 is engaged in the portions of the channel 19which extends parallel to the shaft 14, the blade carrier 10 is movedlinearly so that the blade carried thereby is moved across the glass ofthe windscreen in a direction at right angles to the plane of the bladeedge.

When the roller 20 reaches the extension 22 of the channel 19, however,the blade carrier 10 and blade are moved angularly so that the bladecarrier out arcuate movement and finally reaches a position. in which itis substantially parallel with the axis of the shaft 14. This representsthe parked position of the blade.

In the example illustrated, the extension 22 of the channel has aportion at its end which is substantially parallel with the straightportion of the channel 19, but off-set therefrom. When the rolleroccupies this portion, the blade will occupy a position which issubstantially parallel with the shaft axis and will be moved in thatdirection.

This portion of the extension 22 is necessary so that a second bladecontrolled by a similar mechanism, and moving in an arc which overlapswith the arc of the blade described, and in the parked position, willoverlie it. If no such portion of the extension 22 is provided on one ofthe channels for the rollers 20 of the respective mechanisms, the bladeswill tend to interfere.

A preferred apparatus comprises two mechanisms operable in unison from asingle drive shaft.

FIG. 4 represents a diagrammatic view of the portions of a windscreenwhich can be swept by means of blades operated by mechanisms, asdescribed, each of the swept areas defining a rectangular portion and aquarter circular portion.

In FIG. 3 there is represented another mechanism which is capable ofproducing similar wiping cycle to the FIG. 4 representation. In FIG. 3there are two pairs of pulleys 23, 24, 25, 26. The inner pair of pulleys25, 26 are driven by a motor 27. Also engaging with each pair of pulleysis a cable 28, 29, carrying a blade carrier 30 and 31 respectively.Linear and angular movement of the blade carriers 3t and 31 is guided bythe guide channel arrangement which is shown in the FIGS. 1 and 2construction.

FIG. 6 represents wiped areas in an alternative arrangement in which thequarter circular portion in one area overlaps a part of the rectangularportion of the other area. A mechanism for producing such movement isshown in FIG. 5. This includes a pair of pulleys 32, 33 on which ismounted a cable. One of the pulleys is driven by a reversable drivemechanism. The cable carries a pair of blade carriers 34, 35, which aremoved linearly along the cable upper reach. Mechanism (not shown)similar to the channel guide means of the FIG. 1 and 2 construction, isprovided whereby the blade carriers 34 and 35, or parts connectedthereto are moved angularly at the ends of the travel.

In an alternative arrangement the cables are replaced by metal stripsrunning on pulleys.

In a further alternative arrangement there is a drive shaft similar tothat illustrated in FIG. 1 having only one helical groove. The electricmotor which drives the shaft is reversable and at the ends of the travelof the blade carrier the motor is reversed by appropriate switchmechanism.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

l. A mechanism for controlling the operating cycle of a wiper blade fora vehicle windscreen comprising a wiper blade carrier, means for movingthe carrier substantially linearly with respect to one edge of thewindscreen to be cleaned, and guide means whereby said linear movementis converted into angular movement of the blade carrier over a portionof the cycle, the guide means comprising a member defining a channelextending lengthwise of the windscreen edge, said channel having, nearone end, an off set extension, the carrier having an element engageablewith the channel, whereby whenthe element reaches said off setextension, the blade carrier is caused to execute angular motion.

2. A mechanism as claimed in claim 1 in which the means for moving thecarrier substantially linearly comprises a rotatable drive shaft formedwith a continuous groove extending helically with respect to the axis ofrotation of the shaft, the carrier having an element engageable withsaid groove so that as the shaft is rotated, the carrier moveslengthwise of the shaft.

3. A mechanism as claimed in claim 1 in which the extension of thechannel is S-shaped.

4. A mechanism as claimed in claim 1 in which the member defining thechannel is a rail having a portion interengaging with a formation on theblade carrier to prevent tilting of the carrier.

5. A mechanism as claimed in claim 1 in which there are two bladecarriers operated by respective mechanisms from a single drive shaft.

6. A mechanism as claimed in claim 1 in which two blade carriers areconnected to respective belts engaging pairs of pulleys respectively,the motion of the carriers being achieved by movement of the carrierswith the belts between the pulleys, and linear and angular movement ofthe carriers being guided by guide channel means.

7. A mechanism as claimed in claim 1 in which the drive means comprisesa belt or cable to which the blade carrier or more than one bladecarrier is or are attached, the belt or cable being engaged on a pair ofpulleys, one of which is driven in opposite directions alternately by areversible drive mechanism.

1. A mechanism for controlling the operating cycle of a wiper blade fora vehicle windscreen comprising a wiper blade carrier, means for movingthe carrier substantially linearly with respect to one edge of thewindscreen to be cleaned, and guide means whereby said linear movementis converted into angular movement of the blade carrier over a portionof the cycle, the guide means comprising a member defining a channelextending lengthwise of the windscreen edge, said channel having, nearone end, an off set extension, the carrier having an element engageablewith the channel, whereby when the element reaches said off setextension, the blade carrier is caused to execute angular motion.
 2. Amechanism as claimed in claim 1 in which the means for moving thecarrier substantially linearly comprises a rotatable drive shaft formedwith a continuous groove extending helically with respect to the axis ofrotation of the shaft, the carrier having an element engageable withsaid groove so that as the shaft is rotated, the carrier moveslengthwise of the shaft.
 3. A mechanism as claimed in claim 1 in whichthe extension of the channel is S-shaped.
 4. A mechanism as claimed inclaim 1 in which the member defining the channel is a rail having aportion interengaging with a formation on the blade carrier to preventtilting of the carrier.
 5. A mechanism as claimed in claim 1 in whichthere are two blade carriers operated by respective mechanisms from asingle drive shaft.
 6. A mechanism as claimed in claim 1 in which twoblade carriers are connected to respective belts engaging pairs ofpulleys respectively, the motion of the carriers being achieved bymovement of the carriers with the belts between the pulleys, and linearand angular movement of the carriers being guided by guide channelmeans.
 7. A mechanism as claimed in claim 1 in which the drive meanscomprises a belt or cable to which the blade carrier or more than oneblade carrier is or are attached, the belt or cable being engaged on apair of pulleys, one of which is driven in opposite directionsalternately by a reversible drive mechanism.